Place potatoes in a pot of cold water with a good pinch of salt. Bring to the boil and cook potatoes for 3 minutes, until just cooked through, and drain.
Heat half the olive oil in a large fry pan and add onion, cook for a few minutes until soft. Add remaining olive oil, curry powder and cooked potatoes, stir and cook a few minutes. Add spinach and lemon juice and toss with potatoes until the spinach has wilted, 1-2 minutes. Season with salt and pepper to taste.
Heat a separate fry pan on medium heat and fry Haloumi slices 1-2 minutes on each side until golden brown, and soft on the inside.
Bring a medium sized saucepan of water to a gentle boil, reduce to a simmer, and carefully crack in eggs. Poach for 1-2 minutes until whites are just set, but yolk is still runny.
Mix mayonnaise with yoghurt.
To serve, divide potato mixture between plates, top with a poached egg and 2 slices of haloumi. Garnish with coriander and serve with a dollop of yoghurt mayonnaise to the side.